The Researches On Damage Mechanisms Of Nanosecond/Continuous Laser Irradiation On CCD Detector

In recent years,with the development of optoelectronic technology,CCD is the core component of optical imaging system and detection system,and it has been widely used in daily life,national defense and military fields.Especially in modern warfare,CCD also plays an indispensable role.High-altitude reconnaissance,infrared guidance,night vision equipment and safety monitoring rely on the imaging function of CCD.Therefore,it has been great significance for the photoelectric countermeasures that how to effectively damage the CCD in the military.At present,the research on laser-damaged CCD generally uses pulsed laser or continuous laser,and the damage efficiency of the two is not high.Therefore,in order to be able to damage the CCD efficiently,it is certain significance to use the nanosecond pulse/continuous laser for studying the damage of the CCD.In this paper,the research work of nanosecond pulse/continuous laser on CCD damage mechanism was carried out.Based on the theory of heat conduction,the finite element simulation software COMSOL Multiphysics was used to simulate the temperature changes during nanosecond pulsed laser,continuous laser and nanosecond pulse/continuous laser irradiation.The energy/power of nanosecond pulsed laser and continuous laser was discussed.And the influence of the spot radius on the temperature rise and the influence of the nanosecond pulse injection time on the temperature rise during the nanosecond pulse/continuous laser action CCD process.As the laser energy density/power density increases,the CCD center point temperature increased.Experiments on damage of CCD by nanosecond pulsed laser and continuous laser were carried out.In the nanosecond laser damage CCD,with the increase of laser energy,point damage,line damage and surface damage(completed damage)appeared in the CCD functional damage.The damage threshold of the CCD detector was measured and it was found that the surface topography damage threshold was greater than the functional damage threshold.When the continuous laser damages the CCD,only the surface damage occured in the CCD function damage.The results of nanosecond pulse laser and continuous laser damage CCD showed that the functional damage threshold and topographic damage threshold of the CCD detector with protective sheet were higher than that without protective sheet CCD.The damage experiment of nanosecond pulse/continuous laser damage CCD was carried out.Compared to nanosecond pulsed laser and continuous laser damage CCD,the result showed that the nanosecond pulse/continuous laser action CCD detector reduced the surface damage threshold.Combined with the experimental results,the damage mechanism of nanosecond pulsed laser,continuous laser and nanosecond pulse/continuous laser to CCD was analyzed.